Fully-textile polymer-based ECG electrodes: overcoming the limits of metal-based textiles

In recent years, there has been a particular interest in wearable electronics for electrocardiogram (ECG) recording. The ultimate goal is the integration of both sensors and electronics in clothes, for both clinical and non-clinical use. To date, textile ECG electrodes have been mainly based on the use of conductive metal fibers woven or stitched on a finished substrate. In this work, textiles electrodes for ECG are obtained by treating finished fabrics with the conductive organic polymer poly-3,4-ethylenedioxythiophene doped with poly(styrene sulfonate) (PEDOT:PSS). Compared to previous works based on the treatment of a whole piece of fabric by immersion in the PEDOT:PSS solution, the adoption of a novel screen printing technique enables to achieve good definition and control over the quantity of deposited polymer. The proposed fabrication approach compares favorably with the previous one. A small trial with 10 subjects, aimed to record 12-lead ECG traces with clinical instrumentation, revealed the capability of the proposed electrodes to accurately capture the ECG signal morphology with performance comparable to off-the-shelf disposable gelled Ag/AgCl electrodes.